3D-Printed ROS-Scavenging, Proangiogenic, and Biodegradable Hydrogel for Enhancing Burn Wound Healing.

Burns present unique challenges for wound dressing due to excessive reactive oxygen species (ROS), severe vascular damage, and irregular wound shapes. To address this we 3D-printed a bioabsorbable dressing with antioxidant, antimicrobial, proangiogenic, and moisture-retentive properties. By grafting gallic acid (GA) and methacrylic acid (MA) onto gelatin (Gel), we conferredROS-scavenging and UV polymerization properties, respectively. More importantly, the incorporation of GA significantly improved the rheological properties of the GelGA-GelMA bioink, ensuring the printability of the scaffolds in customizable shapes. Owing to its antioxidant properties, GelGA-GelMA eliminated approximately 55% of 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals within 60 min. Benefiting from the degradability of GelGA-GelMA, a proangiogenic drug, 2-deoxy-d-ribose (2dDR), can be controllably released, leading to a 9-fold increase in the number of blood vessel segments. In vivo experiments confirmed that using the GelGA-GelMA hydrogel as a dressing significantly reduced ROS levels and increased CD31 expression in burn wounds, thereby promoting angiogenesis, collagen deposition, and tissue regeneration. We believe that the GelGA-GelMA hydrogel could serve as a promising multifunctional dressing for enhancing burn wound healing.